A bearing assembly of the above-described type is known from U.S. Pat. No. 3,833,277 A, U.S. Pat. No. 3,572,379 A, DE 10 2004 052 684 A1, DE 10 2007 020 007 A1, US 2012/0219246 A1, EP 2 495 467 A2, DE 199 35 014 B4, EP 1 881 243 A1, DE 195 43 571 A1, and DE 10 2011 011 165 A1 show similar and other solutions.
In particular with sealed large bearings, depending on size, changes in the pressure in the interior of the bearing assembly relative to the ambient pressure arise due to temperature changes even more than in normal-sized bearings. This is caused by, among other things, different thermal expansions of air and lubricant and of the steel rings of the bearing. If the bearing is provided with seals, this pressure negatively affects the function of the seals. The results are greater wear and higher friction. Furthermore, the seal effect can also be negatively influenced.
A pressure difference between the bearing interior and the environment can also act in a direction for which the seal function was not constructed. In this case, for example, moisture or contaminants can penetrate into the bearing.
It is known to provide in the bearing assembly outlet bores for excess lubricating grease that are connected to collecting systems on the bearing assembly. Lubricant is discharged from the bearing through these outlet systems. However, for this purpose a certain overpressure is required in the bearing in order to press the lubricant through the required lines in the collecting container. The outlet bore can also be clogged by excess lubricating grease such that an influencing of the pressure in the interior of the bearing assembly is not possible therewith.